1. Field of the Invention
The present invention relates to a vertical aligned mode liquid crystal panel, and a liquid crystal display device.
2. Description of the Related Art
In the liquid crystal panel having a liquid crystal layer in vertical aligned mode, the long axis of the liquid crystal material is aligned substantially perpendicularly to its substrate surface when no voltage is applied thereto. Thus, when the liquid crystal panel is watched in the direction perpendicular to the substrate, the panel usually makes it possible to attain substantially complete black display to realize a high contrast.
However, when the vertical aligned mode liquid crystal panel is obliquely watched, there remains a problem that coloration is generated in black display by light leakage.
This problem is caused by both of an apparent shift of axes of its two polarizers arranged under a cross nicol condition and the thickness direction retardation of the liquid crystal cell.
Known is a liquid crystal panel in which in order to compensate for the axis shift of the polarizers, a retardation film is arranged which exhibits a characteristic that the film gives a substantially smaller retardation for a shorter wavelength, and further in order to compensate for the thickness direction retardation of the liquid crystal cell, a retardation film is arranged which exhibits a characteristic that the film gives a substantially larger retardation for a shorter wavelength (see Patent Document 1 as referred to hereinafter). In short, in this liquid crystal panel are arranged at least two retardation films having retardation wavelength-dispersion curves reverse to each other.
However, in the liquid crystal panel in the prior art, it is indispensable to arrange the two retardation films, which have different optical characteristics; therefore, the total thickness of the liquid crystal panel becomes large so that the liquid crystal panel cannot cope with a demand that liquid crystal panels should be made thin. Furthermore, the cost of this liquid crystal panel is high.    Patent Document 1: WO 2003/032060